Hitch mechanisms for trailers have taken a wide variety of different forms. For example, one type of mechanism used when the trailer is being attached to a tractor, includes a "V" opening to receive the king pin of the trailer when the tractor is being moved into position. After the king pin has been inserted into the opening, the hitch mechanism is closed to maintain the trailer attached to the tractor.
On so-called "piggy back" systems, a trailer is carried by a freight car. In these cases, the trailer is generally physically lifted, moved over the freight car and then lowered vertically with the king pin of the trailer being lowered into an opening of the hitch mechanism mounted to the freight car.
In the past, many such hitch mechanisms used in "piggy back" systems have involved movable locking elements which are opened or closed by screw mechanisms. For example, when the hitch is opened, a screw mechanism is in a first position. After the king pin of the trailer has been lowered into the opening of the hitch, a wrench is used to turn the screw mechanism to close the hitch. Additional safety means are sometimes then employed to maintain the hitch in a locked position.
The present invention is directed toward mechanisms specifically designed for freight cars for receiving and transporting a trailer. While the hitch mechanisms used heretofore have proven satisfactory in many cases, they have often required special tools to open and close the hitches. This sometimes is inconvenient and time consuming. Also, the additional safety means used to keep the hitch mechanisms closed often required a conscious manual operation of the person operating the hitch, an operation which may be overlooked.